Top 10 Questions to Ask Before Hiring a Blockchain Developer

Hiring a blockchain developer isn’t just about scanning resumes or ticking off buzzwords like “Solidity,” “DeFi,” or “smart contracts.” The right hire a blockchain developer can be the difference between a secure, scalable dApp and one that crashes on launch or gets exploited. Whether you’re building a smart contract, launching a dApp, or rolling out a full-blown Web3 ecosystem, getting the hiring decision right is everything.

And the competition is heating up…

According to LinkedIn’s Emerging Jobs Report 2024, global demand for blockchain developers grew by 88% year-over-year from 2023 to 2024. The space is booming but so is the number of underqualified developers jumping in. In short, knowing how to hire a blockchain developer isn’t optional anymore but it’s a strategic edge.

Why These 10 Questions Matter?

• They help differentiate pros from pretenders

• Uncover real-world experience, not just theoretical knowledge

• Align your developer’s mindset with your business goals

• Save you time, money, and future headaches

Top 10 Questions to Ask Blockchain Developers in 2025

1. What blockchain platforms have you worked with (Ethereum, BNB Chain, Polygon, etc.)?

Why ask: Each platform has unique architecture, fees, and scalability. You want someone who’s actually shipped projects on your preferred chain.

Red flag: “I’ve only done tutorials” or “I can learn fast.”

2. Can you walk me through a smart contract you’ve built?

Why ask: You want proof of real experience, not just hype.

Bonus tip: Ask them to explain the contract’s security model and audit process.

3. How do you handle smart contract vulnerabilities like reentrancy or gas limit issues?

Why ask: Security is non-negotiable in blockchain.

Look for: Understanding of known attack vectors, use of testnets, and tools like MythX, Slither, or OpenZeppelin.

4. Have you worked with token standards like ERC-20, ERC-721, or ERC-1155?

Why ask: If you’re building anything involving tokens or NFTs, they need fluency in these standards.

Ideal answer: Yes, I’ve implemented custom ERC-721 contracts for an NFT project with lazy minting.

5. What is your approach to testing and deployment?

Why ask: Smart contracts are immutable once deployed. A good dev uses Truffle, Hardhat, or Foundry, tests on testnets, and writes automated tests.

Great Answer: I test with Hardhat or Foundry, deploy to testnets, use Slither for security, and automate with CI/CD.

6. Can you explain your experience with decentralized storage (IPFS, Arweave, etc.)?

Why ask: Web3 isn’t just code but it’s assets and data need storage too. One study shows that more than 64% of blockchain projects in 2024 reported delays due to poor hiring choices or inexperienced developers.

Look for: “I’ve used IPFS for off-chain NFT metadata,” etc.

7. How do you ensure your code is gas efficient and scalable?

Why ask: High gas fees = poor UX = lost users.

Good answer: “I optimize for storage, avoid loops, and use structs wisely.”

8. Have you contributed to any open-source Web3 projects or DAOs?

Why ask: Active community contributors often stay updated with the latest standards and best practices.

Bonus: GitHub is your secret weapon. Resumes can be polished. Interviews can be rehearsed. But a GitHub profile? That’s raw, real, and almost impossible to fake. So, Check their GitHub.

9. How do you stay updated with evolving blockchain tech?

Why ask: Let’s be real that Web3 doesn’t just evolve but it explodes forward every single week. New protocols emerge. Layer 2 solutions roll out faster. Security standards change. Regulatory shifts happen globally. And if you’re not staying updated, you’re falling behind fast.

Great answer: “I follow ETHGlobal events, read Vitalik’s blog, and experiment with zk tech.”

10. What challenges have you faced in past blockchain projects and how did you solve them?

Why ask: Problem-solving is what separates coders from creators.

Real talk: Look for stories about mainnet bugs, testnet surprises, governance issues, or cross-chain headaches and how they overcame them.

Bonus Questions Especially for Startups:

• How comfortable are you working in agile or lean startup environments?

• Do you prefer working solo or with a product team?

• Can you handle both on-chain and off-chain architecture?

Sample Blockchain Developer Interview Flow

Pro Tip: Hire for Mindset, Not Just Skills

Blockchain is new, volatile, and ever-evolving. Choose developers who:

• Learn quickly

• Write clean, auditable code

• Understand the why behind the tech

• Care about decentralization, security, and user experience

Looking to Hire a Blockchain Developer Whom You Can Trust?

At Velvosoft, we’ve handpicked and trained a world-class team of blockchain developers who’ve:

• Delivered dApps on Ethereum, BNB Chain, and Polygon

• Built NFT marketplaces, DeFi platforms, and DAO tools

• Written audited smart contracts for projects in 7+ countries

Talk to us today and avoid costly hiring mistakes.

Related Reads

• Ethereum vs BNB Chain vs Polygon: Which One’s Best for Your dApp?

• CApps vs DApps: What Founders Need to Know in 2025

• What if Gmail Was Built on Web3?

FAQs: How to Hire a Blockchain Developer

Q. What skills should a blockchain developer have in 2025?
A. Smart contract knowledge, platform expertise (Ethereum, Solana, etc.), security practices, gas optimization, and Web3 tooling (Hardhat, Foundry, IPFS, etc.)

Q. How much experience is ideal when hiring a blockchain developer?
A. At least 1–2 years of hands-on smart contract or dApp development experience. Portfolio is more important than years.

Q. Should I hire freelance or in-house developers?
A. Start with freelance or remote developers for MVPs. Go in-house for full products or if you require NDA/compliance controls.

Q. How long does it take to hire a good blockchain developer?
A. It typically takes 2–6 weeks depending on your hiring model. Vetting, technical interviews, code reviews, and blockchain-specific assessments are crucial for finding the right fit.

Q.How do I verify a blockchain developer’s credibility?
A. Check their GitHub, deployed smart contracts (on Etherscan, Polygonscan, etc.), portfolio websites, contributions to open-source protocols, and ask for code samples or a short build test.

Q. What are the red flags when hiring a blockchain developer?
A. Red flags include:

• No GitHub activity or public repos

• Only tutorial-based projects, no mainnet deployments

• Lack of understanding of security vulnerabilities (like reentrancy, front-running)

• Inability to explain gas optimization techniques

• No familiarity with testnets or dev tooling